Rinse the urid dal, then add water to soak it. The dal swells, hence use a bigger bowl and add about 2.5 cups of water.
Similarly, rinse the rice and soak it with a knuckle of water above the rice level.
Rinse and soak the sago in a bowl. As the sago swells, use a bigger bowl and add a knuckle of water above the sago level.
Soak them for 5-6 hours.
Grinding and fermenting
After the soaking time ends, grind the dal and the sago to a fine paste. If, like me, you are using a mixer grinder, add some ice cubes. The dal batter needs to be ground with minimal water, so add water/ice sparingly.
Transfer to a big mixing bowl.
Next, grind the rice with minimal water to a fine rava or semolina texture.
Add the rice paste to the bowl with urid dal and sago paste. Mix well using your fingers. There should be no lumps in the mixture.
Cover and let the batter ferment for about 8-12 hours.
Making the Mallige Idlis
When you are ready to make your idlis, grease the idli stand with oil.
Set up your steamer, add water to the base pan, and bring it to a boil.